A dishwasher of this kind is generally known from German patent specifications DE 102 01 792 C1 and DE 102 04 548 A1.
For the prevention of lime deposits on dishes it is known to soften the water entering the dish washing chamber of a dishwasher by feeding it through an ion exchanger. In household dishwashers, the ion exchanger usually is provided with a mixed bed resin, the softening components of which will become exhausted and require replenishment by a salt solution. For receiving a supply of salt sufficient for several regeneration cycles, a water softener is provided with a salt container in addition to the ion exchanger. It is known and generally practiced in commercial dishwashers to arrange the salt container at the bottom of the housing of the apparatus and to charge or fill it through an opening in the bottom panel of the washing chamber. For a user, this is uncomfortable or inconvenient since it compels him to reach deeply into the washing chamber. The disadvantage is greater still when lacking salt is detected while the machine is filled with dishes. In such a case, the lower dish basket must first be unloaded before it can may be removed from the washing chamber to provide free access to the filling opening of the salt container. To avoid these disadvantages, German patent specification DE 102 01 792 C1 and DE 102 04 548 A1 propose to position the salt container within the door of the apparatus for filling it in a simple manner through a salt feed opening at the interior surface of the door. Owing to the narrow space between the inner and outer surface panels of the door, the design of such a salt container has to be very thin. Because of the arrangement of the salt fill opening in the front wall which is vertically disposed when the door is closed during operation, the salt container cannot be filled completely with salt or fluid. For that reason an air cushion will form above the brine. During operation of the dishwasher the air cushion will expand as a result of a rise in temperature.
German patent specification DE 692 01 234 discloses a brine preparation arrangement integrated into the door of an apparatus which at the output of the regenerating water dispenser allows a temperature-affected medium to escape through a channel leading to the interior of the washing chamber. The output tube of the channels forms a syphon which prevents balancing of the air between the salt container and the environment.
Another problem arises in handling dishwashers where it is necessary for purposes of a repair to change their upright operating disposition and place the machine on its back, one of its side surfaces, or even on its top surface, or where the position of the machine is changed during transport. In such cases it is practically impossible to prevent the brine from escaping from the salt container through the vent opening.